Most modern water heaters are constructed of a steel tank with a glass lining. Passive anode rods are a vital component to water heaters utilizing a steel tank or other forms of tanks susceptible to corrosion. An anode rod can act as a sacrificial anode that provides protection against tank corrosion. In particular, the anode rod acts as a sacrificial anode by way of galvanic corrosion.
As a result of the galvanic corrosion, a galvanic current can flow from the anode rod to a cathode to which the anode rod is electrically connected. The cathode is commonly the exterior of the tank connected to an earth ground. The anode rod is depleted by the galvanic corrosion and therefore acts as a sacrificial anode.
Water heaters also frequently include one or more heating elements positioned inside the tank and configured to heat water stored in the tank. For example, a heating element can provide heat by way of electrical resistance. The heating element can resist an electrical current and therefore generate heat, raising the temperature of the water.
It is important to the proper operation of a water heater that an energization status of each heating element included in the water heater be known or able to be determined. In particular, to properly heat the water to a desired temperature and avoid dangerous conditions such as scalding water, a water heater must be able to determine whether or not a heating element is currently energized.
One particularly dangerous condition which must be avoided is operation of a heating element in a “dry tank.” More particularly, as discussed above, a heating element can be used to dissipate or provide a significant amount of heat. When the heating element is submerged in water, the water surrounding the heating element safely accepts or absorbs such heat.
However, when the water in the tank is depleted through use or otherwise reduced to a level where the heating element is no longer submerged, operation of the heating element can be dangerous. In particular, the heating element can overheat and catch fire, among other dangers.
Therefore, improved systems and methods for determining heating element and water heater status are desirable. In particular, improved systems and methods for determining heating element and water heater status which leverage the presence of a galvanic current are desirable.